Special purpose fluid dispenser

ABSTRACT

A compact, nonelectric fluid dispenser for use in controllably dispensing beneficial agents such as propofol and dexmedetomidine hydrochloride to patients. The dispenser includes a fluid flow control assembly that precisely controls the flow of the medicament solution to the patient and embodies a collapsible drug container that can be filled in the field with the beneficial agents to be delivered to the patient. The unit-dose fluid dispenser of the invention is presented in a sterile and aseptic manner, where the drug has been pre-filled in the system, so that the practitioner cannot mistakenly give the wrong drug to the patient. The dispenser uniquely provides a more efficient medicament delivery system for procedure rooms, such as the endoscopy center, so that a greater number of patients can be treated per day at a higher standard of care with increased profits for the healthcare provider.

FIELD OF THE INVENTION

The present invention relates generally to fluid dispensing devices.More particularly, the invention concerns a novel dispenser fordispensing propofol, as well as analogous sedation agents, to patientswith increased safety and efficiency while reducing the probability ofhospital acquired infections.

DISCUSSION OF THE PRIOR ART

A number of different types of medicament dispensers for dispensingvarious types of medicaments to patients have been suggested in thepast. The traditional prior art infusion methods make use of a flexibleinfusion bag suspended above the patient. Such gravametric methods arecumbersome, imprecise, require many time consuming steps by clinicians,are susceptible to medication errors and require bed confinement of thepatient. Periodic monitoring of the apparatus by the nurse or doctor isrequired to detect malfunctions of the infusion apparatus. Accordingly,the prior art devices are not well suited for use in those instanceswhere the patient must be transported from one part of the healthcarefacility to another.

Many of the state-of-the-art medicament delivery devices involve the useof electronic pumps to dispense the medicament from the dispenserreservoir. In the past, these types of devices have been the devices ofchoice for dispensing propofol (and other injectable sedation agents)and this equipment requires significant effort to prepare and administerthe drug.

Propofol is a highly protein bound in vivo and is metabolised byconjugation in the liver. Its rate of clearance exceeds hepatic bloodflow, suggesting an extrahepatic site of elimination as well. Itsmechanism of action is uncertain, but it is postulated that its primaryeffect may be potentiation of the GABA—a receptor, possibly by slowingthe closing channel time. Recent research has also suggested theendocannabinoid system may contribute significantly to Propofol'sanesthetic action and to its unique properties.

In recent years propofol has been widely used as an anesthetic agent forthe induction of general anesthesia in adult patients and pediatricpatients older than 3 years of age, for use in the maintenance ofgeneral anesthesia in adult patients and pediatric patients older than 2months of age, for use in sedation for intubated, mechanicallyventilated adults, and in procedures such as colonoscopy.

At the present time, propofol is commonly delivered through anelectronic pump that is preset with the patient's weight (in kg) and adosage increment measured in micrograms/kg/min. One prior art electronicpump that is presently in use is a pump sold by Baxter International,Inc, of Deerfield, Ill. under the name and style “InfusO.R.”. This pumpcontains four separate dials. The first dial is to set the patientweight; the second dial is to set the dosage; the third dial is to set abolus volume to initiate sedation; and the fourth dial is used to purgethe syringe if there is any remaining propofol after the procedure. TheBaxter pump has a magnetic plate that contains all the increments of thedials and the plates can be changed for different medications. By havingremovable plates, there is an increased possibility of medication errorif the magnetic plate is not checked for increments for the correctmedication or the correct concentration. The Baxter pump is typicallyused in the surgicenter setting where the anesthesiologist gives thepatient an initial bolus of propofol for inducing sedation and thepreset dosage is given in addition to gas anesthesia to keep the patientasleep during the operation. Another pump that is presently in use is apump sold by the Cardinal Health Company of Dublin, Ohio under the nameand style “ALARIS PL”. The ALARIS PL syringe pump or ALARIS IVAC pump isused in conjunction with a Diprifusor syringe that is pre-filled withpropofol. The Diprifusor is a target controlled infusion (TCI) systemthat was developed to enhance the control of IV anesthesia. With a TCIpump, a microprocessor manages the infusion rate and controls thesyringe. The anesthesiologist enters the body weight of the patient, theage of the patient, and the dosage in microgram/ml. The Alaris pumpsrely on the anesthesiologist entering the correct data minimizing thepossibility of medication error but the dosage form is not the commonlyused increment, (microgram/ml instead of microgram/kg/min) which relieson the anesthesiologist to convert the dosage and potentially increasesthe risk of medication error through miscalculation. The Diprifusor andTCI pumps are typically used in Europe where the pump is used to controlsedation and anesthesia, but are thus far not dominant in the Americansurgical market.

As will be discussed in greater detail hereinafter, the propofoldispenser of the present invention allows the anesthesiologist to createa basic “recipe” for propofol based sedation that could prevent patientcomplications. The dispenser of the present invention is particularlywell-suited for use in the administration of propofol bynon-anesthesiologists in low risk procedures, such as colonoscopies.

Another pharmaceutical agent appropriate for use in this novel dispensertechnology is dexmedetomidine hydrochloride (Precedex), and relatedcompounds. Precedex is indicated for sedation of initially intubated andmechanically ventilated patients during treatment in an intensive caresetting. Precedex is typically administered by continuous infusion usinga syringe of the drug fluid (drawn up in a non-aseptic environment bythe anesthesiologist) and dispensed by an electronic pump. Precedex isbeing used with patients in the intensive care unit (ICU), duringneurosurgery and for children during MRI.

Precedex is delivered via intravenous infusion over a selected amount oftime through a controlled infusion with the use of an electronic orbattery operated pump or with a “smart pump”. A pre-filled andnon-electric pump that is therapy specific could allow more widespreaduse of novel sedation agents (such as Precedex), because of the abilityto administer the therapy in a safer and more efficient manner withoutthe need for multiple steps and sophisticated software routines.

The novel dispenser of the present invention provides numerousadvantages over prior art devices including the following:

Creation of a standard operating procedure for the administration ofpropofol by anesthesiologists and non-anesthesiologists alike.

Elimination of the need for filling syringes, thereby reducing thepotential for medication errors due to filling (i.e. using the wrongconcentration of propofol) or use of a drug that is similar inappearance to propofol.

Elimination of the need for an electronic pump, thereby reducing thepotential for medication error due to incorrect settings.

Reducing costs to healthcare providers and practitioners by eliminatingexpensive electronic capital equipment that requires continuousmaintenance, calibration and cleaning.

Elimination of the requirement for electricity in austere or chaoticenvironments (e.g. during military engagements, natural disasters).

Presentation of the sedation agent at the point of care in an asepticmanner (via the field fill design where the dispenser is filled at timeof use by engagement of the drug and device through a polarized sterilecoupling), should also minimize the probability of hospital acquiredinfection.

As previously mentioned, a significant market for the small volumedispenser of the present invention is the endoscopy center market. Inthis regard, one form of the dispenser of the present invention isspecially designed for relatively short procedures (i.e. 20-30 minutes),such as colonoscopies and endoscopies. More particularly, the dispenserof the invention, which is non-electric and disposable following use,can provide an extremely cost effective means of increasing efficiencyin the endoscopy center. The dispenser uniquely provides an alternativeto expensive electronic pumps that are often complicated and timeconsuming to operate. In addition, low cost disposable devices for usein outpatient clinics are consistent with a broader theme in healthcarethat is aimed at lowering costs while improving quality of care andpatient outcomes. Because physicians in the endoscopy center aresearching for a cost effective means to increase patient throughputwithin the center, the dispenser of the present invention provides anatural fit for a standardized sedation process for colonoscopies andendoscopies, without compromising the quality and safety of theprocedure.

In another form of the present invention, the dispenser comprises amid-volume propofol delivery systems technology (65 ml) that isspecially designed for use in the surgicenter for procedures thatrequire sedation times of 1-2 hours. In this application a noveldispenser can serve as a safe and effective means for patients that areto be fitted with orthopedic and cardiac implants. Similarly, this novelmid-volume dispenser can function well with minimum discomfort forgeneral surgeries such as hernia repairs and the like. Becausephysicians in the surgicenter market are often quite time conscious, thedispenser of the present invention comprises a natural fit for astandardized sedation process that could potentially increase patientthroughput within the market without compromising the quality and safetyof the procedure. Additionally, patients prefer propofol as ananesthetic agent because there is no “hangover” effect, which stems fromits ease of titration and rapid elimination half-life. By way ofcomparison, traditional anesthesia with gas has a very slow eliminationhalf-life and patients require long recovery times that are typicallycomplicated by nausea and vomiting. Conversely, propofol has inherentantiemetic properties, which chemically combats feelings of nausea.

In yet another form of the present invention, the dispenser comprises alarge volume propofol dispenser (250 ml) that is specially designed foruse in military applications, including total IV anesthesia (TIVA) bythe Forward Surgical Team at the battlefield, as well as for sedation ofthe patient during transport from one echelon of care to the next. Thisform of the invention can provide a safe and effective means to sedate apatient during an operation and throughout transport without relying onbulky medical equipment or expensive equipment that is transported withthe patient and never returned to the original care facility.

As will be fully appreciated from the discussion that follows, thedevices of the present invention are also particularly useful inambulatory situations. The ability to quickly and efficaciously treatwounded soldiers, especially in unpredictable or remote care settings,can significantly improve chances for patient survival and recovery.Accurate intravenous (IV) drug and fluid delivery technologies forcontrolling pain, preventing infection, and providing a means for IVaccess for rapid infusions during patient transport are needed to treatalmost all serious injuries.

It is imperative that battlefield medics begin administering life savingmedications as soon as possible after a casualty occurs. The continuousmaintenance of these treatments is vital until higher echelon medicalfacilities can be reached. A compact, portable and ready to use infusiondevice that could be easily brought into the battlefield would allowmedics to begin drug and resuscitation agent infusions immediately.Additionally, it would free them to attend to other seriously woundedpatients who may require more hands-on care in the trauma environmentfollowing triage. In most serious trauma situations on the battlefield,IV drug delivery is required to treat fluid resuscitation, as well asboth pain and infection. Drug infusion devices currently available canimpede administration of IV infusions in remote care settings.

Expensive electronic infusion pumps are not a practical field solutionbecause of their weight and cumbersome size. Moreover, today'sprocedures for starting IV infusions on the battlefield are oftendangerous because the attending medic must complete several timeconsuming steps. The labor intensive nature of current gravity solutionbag modalities can prevent medics from attending to other patients alsosuffering from life threatening injuries. In some cases, patientsthemselves have been forced to hold flexible infusion bags elevated, inorder to receive the medication by gravity drip.

SUMMARY OF THE INVENTION

By way of brief summary, one form of the dispensing device of thepresent invention for dispensing the beneficial agent, such as propofol,to a patient comprises a housing, a carriage assembly disposed withinthe housing, a reservoir defining assembly carried by the carriage, astored energy means operably associated with the carriage for moving thecarriage between a first position and a second position to expel fromthe reservoir the fluid medicament contained therein, and flow controlmeans to control the flow of fluid from the reservoir, the flow controlmeans uniquely comprising dose control means for controlling the dose ofmedicament to be delivered to the patient and rate control means forcontrolling the rate of medicament flow to the patient. This noveldesign would therefore allow the physician to set a medicament flow ratebased on the patient's body weight in kg and the patient appropriatedose in micrograms per kg per hour.

With the forgoing in mind, it is an object of the present invention toprovide a compact, nonelectric fluid dispenser for use in controllablydispensing propofol to patients.

Another object of the invention is to provide a fluid dispenser ofsimple construction that can be used in the field with a minimum amountof training.

Another object of the invention is to allow infusion therapy to beinitiated quickly and easily on the battlefield so that the attendingmedic or medical professional can more efficiently deal with triagesituations in austere environments.

Another object of the invention is to provide a dispenser of the classdescribed which includes a fluid flow control assembly that preciselycontrols the flow of the medicament solution to the patient.

Another object of the invention is to provide a dispenser that includesprecise variable flow rate selection.

Another object of the invention is to provide a fluid dispenser ofsimple construction, which embodies a collapsible drug container thatcan be selectively filled with the beneficial agent at the point ofcare.

Another object of the invention is to provide a fluid dispenser of theclass described which is compact, lightweight, is easy and safe forproviders to use, is fully disposable, transportable, and is extremelyreliable in operation.

Another object of the invention is to provide a fluid dispenser of theclass described that is presented in a sterile and aseptic manner wheredrug filling is conducted at the point of care; so as to minimize theprobability of hospital acquired infections and medication errors.

Another object of the invention is to provide a medicament dispenserthat improves the process efficiency of the healthcare setting bystreamlining the tasks associated with the preparation, administrationand monitoring of drug delivery of regimen.

Another object of the invention is to provide a low cost single-usealternative to expensive electronic pumps that have to be continuallycleaned, calibrated and maintained at tremendous costs to healthcareproviders.

Another object of the invention is to provide a dispenser that canadminister anesthesia and sedation agents to patients withoutproblematic side effects, such as nausea and vomiting, typicallyencountered with traditional gas anesthesia.

Another object of the invention is to provide a more efficientmedicament delivery system for procedure rooms, such as the endoscopycenter, so that a greater number of patients can be treated per day athigher standard of care with increased profits for the healthcareprovider.

Another object of the invention is to provide a fluid dispenser asdescribed in the preceding paragraphs that is easy and inexpensive tomanufacture in large quantities.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a generally perspective front top view of one form of thefluid dispensing device of the present invention for dispensingmedicaments to a patient.

FIG. 2 is a generally perspective rear bottom view of the fluiddispensing device shown in FIG. 1.

FIG. 3 is a top plan view of the fluid dispensing device shown in FIG.1.

FIG. 4 is a side view of the fluid dispensing device shown in FIG. 3.

FIGS. 5 and 5A, when considered together, comprise an enlargedcross-sectional view of the fluid dispensing device shown in FIG. 4 ofthe drawings.

FIG. 6 is an enlarged, top plan view, partly in cross-section, of thecentral portion of the fluid dispensing device shown in FIG. 1.

FIG. 7 is a cross-sectional view taken along lines 7-7 of FIG. 6.

FIG. 7A is a top plan view of the fluid pickup plates of the bolusdelivery subassembly of the apparatus.

FIG. 7B is a cross-sectional view taken along lines 7B-7B of FIG. 7A.

FIG. 8 is a cross-sectional view taken along lines 8-8 of FIG. 7.

FIG. 9 is a cross-sectional view taken along lines 9-9 of FIG. 7.

FIG. 10 is a cross-sectional view taken along lines 10-10 of FIG. 7.

FIG. 11 is a cross-sectional view taken along lines 11-11 of FIG. 7.

FIG. 12 is a top plan view of the patient weight selector knob and thepatient dose selector knob components of the fluid dispensing device.

FIG. 13 is a cross-sectional view taken along lines 13-13 of FIG. 12.

FIG. 14 is a cross-sectional view taken along lines 14-14 of FIG. 12.

FIG. 15 is an enlarged front view of the main body portion of thedispensing apparatus shown in FIG. 1.

FIG. 16 is an enlarged cross-sectional view taken along lines 16-16 ofFIG. 15.

FIG. 17 is an enlarged cross-sectional view taken along lines 17-17 ofFIG. 15.

FIG. 18 is an enlarged cross-sectional view of the rearward portion ofthe fluid dispensing device shown in FIG. 1, further illustratingconstruction of the field filled reservoir portion of the device.

FIG. 19 is a cross-sectional view taken along lines 19-19 of FIG. 18.

FIG. 19A is a generally perspective, diagrammatic view illustrating thepath of fluid flow through the device during the reservoir filling step.

FIG. 20 is an enlarged top plan view of the patient weight selectorsubassembly of the fluid dispensing device.

FIG. 21 is a cross-sectional view taken along lines 21-21 of FIG. 20.

FIG. 22 is an enlarged, generally perspective exploded view of thepatient weight selector subassembly of the fluid dispensing device.

FIG. 23 is a bottom plan view of the upper rate control plate of thepatient weight selector subassembly illustrated in FIG. 22 and showingin phantom lines the main fluid pickup housing of the device.

FIG. 24 is a cross-sectional view taken along lines 24-24 of FIG. 23showing the main fluid pickup housing device in greater detail.

FIG. 25 is a fragmentary view taken along lines 25-25 of FIG. 24 showingonly one half of the main fluid pickup housing and illustrating theconstruction of the anti-rotational grooves thereof.

FIG. 26 is a cross-sectional view taken along lines 26-26 of FIG. 23.

FIG. 27 is a generally diagrammatic view illustrating the main fluidpickup housing of the device shown in the upper portion of FIG. 24 as itwould appear in flat configuration.

FIG. 28 is a top plan view of the fluid connector boss of the fluiddelivery device illustrated in FIG. 22.

FIG. 29 is a side elevation view of the fluid connector boss shown inFIG. 28 illustrating the configuration of the fluid micro pickup of theconnector boss.

FIG. 30 is a cross sectional view taken along lines 30-30 of FIG. 28.

FIG. 31 is a top plan view of the upper rate control plate of thepatient weight selector subassembly illustrated in FIG. 22.

FIG. 32 is a cross-sectional view taken along lines 32-32 of FIG. 31.

FIG. 33 is a cross-sectional view taken along lines 33-33 of FIG. 31.

FIG. 34 is a view taken along lines 34-34 of FIG. 31.

FIG. 35 is a cross-sectional view taken along lines 35-35 of FIG. 31.

FIG. 36 is a top plan view of the rate control plate of the fluiddelivery device illustrated in FIG. 22.

FIG. 37 is a cross-sectional view taken along lines 37-37 of FIG. 36.

FIG. 38 is a view taken along lines 38-38 of FIG. 36.

FIG. 39 is a cross-sectional view taken along lines 39-39 of FIG. 36.

FIG. 40 is a top plan view of the bottom rate control plate of the fluiddelivery device illustrated in FIG. 22.

FIG. 41 is a side elevation view of the rate control assembly retainingcover of the fluid delivery device.

FIG. 42 is a cross-sectional view taken along lines 42-42 of FIG. 41.

FIG. 43 is a cross-sectional view taken along lines 43-43 of FIG. 41.

FIG. 44 is a view taken along lines 44-44 of FIG. 41.

FIG. 45 is a view taken along lines 45-45 of FIG. 41.

FIG. 46 is a top plan view of the patient weight selector knob of thepatient weight selector subassembly of the fluid delivery device.

FIG. 47 is a cross-sectional view taken along lines 47-47 of FIG. 46.

FIG. 47A is a generally diagrammatic view illustrating the portion ofthe patient weight selector knob shown in the lower portion of FIG. 47as it would appear in flat configuration.

FIG. 48 is a cross-sectional view taken along lines 48-48 of FIG. 47.

FIG. 49 is a view taken along lines 49-49 of FIG. 47.

FIG. 49A is a view taken along lines 49A-49A of FIG. 49.

FIG. 50 is a top plan view of the patient dose selector knob of thepatient dose selector subassembly of the fluid delivery device.

FIG. 51 is a view partly in cross-section taken along lines 51-51 ofFIG. 50.

FIG. 52 is a view taken along lines 52-52 of FIG. 51.

FIG. 53 is a generally diagrammatic view illustrating the portion of thepatient dose selector knob shown in the lower portion of FIG. 51 as itwould appear in flat configuration.

FIG. 54 is an end view of the fluid delivery device shown in FIG. 1.

FIG. 55 is a cross-sectional view taken along lines 55-55 of FIG. 54illustrating the construction of the bolus operating mechanism of thefluid delivery device.

FIG. 56 is a fragmentary cross-sectional view illustrating theconstruction of the bolus interlock mechanism of the fluid deliverydevice.

FIG. 57 is a generally perspective, exploded view of the bolus operatingmechanism.

FIG. 58 is a top plan view of the bolus reservoir of the apparatus.

FIG. 59 is a cross-sectional view taken along lines 59-59 of FIG. 58.

FIG. 60 is a view taken along lines 60-60 of FIG. 59.

FIG. 61 is a top plan view of the bolus selector subassembly of theapparatus.

FIG. 62 is a cross-sectional view taken along lines 62-62 of FIG. 61illustrating the construction of the main bolus and secondary plungerassembly portion of the bolus operating mechanism.

FIG. 63 is a view taken along lines 63-63 of FIG. 62.

FIG. 64 is a top view of the main reservoir operating shaft.

FIG. 65 is a cross-sectional view taken along lines 65-65 of FIG. 64.

FIG. 66 is a cross-sectional view taken along lines 66-66 of FIG. 64.

FIG. 67 is a cross-sectional view taken along lines 67-67 of FIG. 64.

FIG. 68 is a cross-sectional view taken along lines 68-68 of FIG. 62.

FIG. 69 is a cross-sectional view taken along lines 69-69 of FIG. 68.

FIG. 70 is a cross-sectional view similar to FIG. 68, but showing theoperating spring of the bolus plunger assembly in a compressedcondition.

FIG. 71 is a cross-sectional view taken along lines 71-71 of FIG. 68.

FIG. 72 is a cross-sectional view taken along lines 72-72 of FIG. 68.

FIG. 73 is a top view of the secondary reservoir operating shaft of thebolus plunger assembly.

FIG. 74 is a cross-sectional view taken along lines 74-74 of FIG. 73.

FIG. 75 is a view taken along lines 75-75 of FIG. 74.

FIG. 76 is a view taken along lines 76-76 of FIG. 74.

FIGS. 77, 78 and 79 are generally perspective views of the bolusoperating mechanism of the invention illustrating the sequential stepsto be followed in operating the mechanism to accomplish the delivery tothe patient of bolus doses.

DESCRIPTION OF THE INVENTION

Referring to the drawings and particularly to FIGS. 1 through 5, oneform of the fluid dispensing apparatus of the present invention fordispensing medicaments such as propofol to a patient is there shown andgenerally designated by the numeral 100. The dispensing apparatus herecomprises a device housing 102 having a forward portion 104, a rearportion 106 and a central portion 107. Device housing 102 can beconstructed from metal, plastic or any suitable material.

Disposed within the rear portion 106 of device housing 102 is a“carriage” assembly 108 that is movable between a first rearwardposition shown in FIG. 5 and a second advanced position. As best seen byreferring to FIGS. 5, 18 and 19, carriage assembly 108 comprises acarriage 110 having a carriage flange 112 to which the novel storedenergy means of the present invention is operably interconnected.Carriage assembly 108 is releasably locked in its first position by anovel locking means the character of which will be described in theparagraphs which follow.

Carried by carriage assembly 108 is a reservoir defining assembly 114that defines a fluid medicament reservoir 115. As illustrated in FIG. 5,reservoir defining assembly 114 includes a front portion 114 a, a rearportion 114 b and an accordion-like, collapsible side wall 114 c thatinterconnects the front and rear portion of the assembly. As illustratedin the drawings, the accordion like side wall 114 c comprises amultiplicity of adjacent generally “V” shaped interconnected folds. Rearportion 114 b of the assembly includes a protuberance 116 that includesa rear wall 116 a. As best seen in FIG. 5, cup-shaped protuberance 116is closely receivable within a cavity 120 formed in carriage 110.Reservoir assembly 115 also includes a forward neck portion 122.

Reservoir 115 has an outlet 124 (see FIG. 5) that is formed in a fluidtransfer block 128 that forms a part of the rear portion 106 of housing102. As illustrated in FIG. 5 of the drawings, fluid transfer block 128includes a reduced diameter portion 128 a to which the front portion 114a of the reservoir defining assembly is sealably interconnected. Fluidtransfer block 128 also includes a fluid fill passageway 130 and a ventpassageway 132 (FIG. 6). Fluid fill passageway 130 is in communicationwith a sterile coupling assembly 134 that as best seen in FIG. 6 of thedrawings is mounted within a cavity 136 formed in fluid transfer block128. Fluid fill passageway 130 as well as sterile coupling assembly 134form a part of the fill means of the invention for filling fluidreservoir 115 with the fluid to be dispensed to the patient. In thepresent form of the invention sterile coupling assembly 134 comprises abody portion 138 that houses a pierceable slit septum 140 and aconventional, umbrella check valve 142. Umbrella check valve 142, whichis housed within a cavity 144 that is in communication with fillpassageway 130, functions to permit fluid flow in a direction towardfluid reservoir 115, but blocks fluid flow in the opposite direction.With this construction, fluid reservoir 115 can be conveniently filledwith propofol or other sedation agents in a conventional manner throughthe use of a conventional syringe “S”, such is that shown in FIG. 19A ofthe drawings having either a sharp, or blunt end needle that is capableof piercing septum 140.

To move carriage assembly 108 from its first at rest position to itssecond advanced position and to thereby controllably expel the fluidfrom the fluid reservoir 115, stored energy means are provided. Thisstored energy means, which is operably associated with carriage assembly108, is here provided in the form of a coil spring 148 that is movablefrom the first compressed position shown in FIG. 5 to a second extendedposition, which causes the carriage assembly to move toward its secondadvanced position and in so doing to cause the collapse of the accordionside wall of the reservoir defining assembly. As the accordion side wallof the reservoir defining assembly collapses, the fluid “F” containedwithin the fluid reservoir 115 will be controllably expelled from thereservoir through the fluid outlet 122. As the fluid is expelled from afluid reservoir, any gases contained within the fluid reservoir will bevented to atmosphere, via passageway 132, through a vent port 146 thatis carried by fluid transfer block 128 (FIG. 6).

To control the flow of fluid from reservoir 115 toward theadministration set 153 of the invention (FIG. 2) and then on to thepatient, novel fluid flow control means are provided. The fluid flowcontrol means, which is carried by the central portion 107 of housing102, here comprises dose control means for controlling the dose ofmedicament to be delivered to the patient and rate control means forcontrolling the rate of medicament flow from collapsible reservoir 115toward the dose control means.

Considering first the rate control means component of the fluid flowcontrol means, as best seen in FIGS. 5, 7, 9 and 20 through 49, thisnovel means here comprises a flow rate control assembly 156 (FIGS. 7 and9) for controlling the rate of fluid flow toward the dose control means.Flow rate control assembly 156 includes a first, or lower rate controlplate 158 and a second, or upper, rate control plate 160 (FIGS. 7, 9, 36and 40). As best seen in FIG. 40, bottom side of rate control plate 160is uniquely provided with a plurality of fluidic micro-channelsidentified in the drawings as 162, 164, 166, 168, 170, 172, 174, 176,178, 180, 182, 184, 186, 188, 190, 192, 194 and 196. Each of the fluidicmicro-channels is also provided with an outlet 162 a, 164 a, 166 a, 168a, 170 a, 172 a, 174 a, 176 a, 178 a, 180 a, 182 a, 184 a, 186 a, 188 a,190 a, 192 a, 194 a and 196 a, respectively.

As best seen in FIG. 36, upper side of rate control plate 160 is alsouniquely provided with a plurality of fluidic micro-channels ofdifferent lengths that are identified in the drawings as 202, 204, 206,208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234 and236. Each of the fluidic micro-channels is also provided with an outlet202 a, 204 a, 206 a, 208 a, 210 a, 212 a, 214 a, 216 a, 218 a, 220 a,222 a, 224 a, 226 a, 228 a, 230 a, 232 a, 234 a and 236 a, respectively.Upper control plate 160 is also provided with inlet ports 250, 252, 254,256, 258, 260, 262, 264, 266, 268, 270, 272, 274, 276, 278, 280, 282 and284 that communicate with the outlet ports 162 a through 196 a of lowerside of control plate 160.

As best seen in FIG. 22, the inlet ports of the upper control plate aswell as the outlet ports thereof communicate with a multiplicity ofspaced apart fluid ports 290 formed in rate control distribution plate292. From fluid ports 290, the fluid flows toward the novel fluid pickuphousing 294 of the invention. As illustrated in FIGS. 23 and 24, fluidpickup housing 294 includes a base 294 a and tower portion 294 b that isprovided with a multiplicity of circumferentially spaced apart generallyvertically extending fluid passageways 296 of varying lengths.

With the construction described in the preceding paragraphs, fluidflowing from the fluid reservoir will fill fluidic micro channels 162through 196 as well as fluidic micro channels 202 through 236 via aninlet port 297 carried by rate control distribution plate 292 (see FIGS.19A, 21 and 22). Fluid flowing through the outlet ports of these fluidicmicro-channels will flow into spaced apart fluid ports 290 formed inrate control distribution plate 292. From fluid ports 290, the fluidwill flow into and fill the circumferentially spaced apart, generallyvertically extending fluid passageways 296 of fluid pickup housing 294(FIGS. 23, 24, 25 and 26). Referring to FIG. 27, which is a depiction ofthe outer surface of fluid pickup housing 294 when viewed in a planarconfiguration, it is to be noted that fluid passageways 296 are arrangedin six spaced part groups of passageways 298, 300, 302, 304, 306 and 308respectively. Each group of passageways is made up of six spaced apartpassageways of a different length, each passageway having an outletlocated at a different height with respect to base 294 a of the fluidpick-up housing (FIG. 24). From a selected one of the six groups offluid passageways 296, the fluid will flow into a group of sixvertically and circumferentially spaced apart inlets 310 (FIGS. 49 and49A) formed in the skirt portion 312 a of a patient weight selector knob312 (see also FIG. 22, which is a depiction of the outer surface of theskirt portion when viewed in a planar configuration). For a purposepresently to be described, the skirt portion 312 a of patient weightselector knob 312 is also provided with six circumferentially spacedapart outlet groups 314, each group having six vertically spaced apartoutlet ports 316. From inlets 310, the fluid will flow into a pluralityof vertically spaced apart, circumferentially extending fluidpassageways 320 formed in a fluid pickup housing 322 (FIGS. 7, 28, 29and 30) that is housed interiorly of the downwardly depending skirt 312a of the patient weight selector knob 312 (see FIGS. 7, 20, 21 and 22),retaining tabs 325 that are disposed to interiorly of skirt 312 a (FIG.47) properly and retain fluid pickup housing 322 within skirt 312 a.

With the construction described in the preceding paragraphs, fluidflowing from the fluid reservoir will fill fluidic micro channels 162through 196 (FIG. 40) as well as fluidic micro channels 202 through 236(FIG. 36), will fill the fluid passageways 296 of fluid pickup housing294 (FIG. 24) and will fill the circumferentially extending fluidpassageways 320 formed in a fluid pickup housing 322 (FIG. 22). Fromfluid passageways 320 the fluid will flow into the vertically spacedapart outlet passageways 316 formed in patient weight selector knob 312(FIG. 7).

When the patient weight selector knob 312 is rotated into the positionshown in FIG. 7, fluid will flow from outlet ports 316 into the sixvertically spaced apart, transversely extending fluid passageways 330formed in fluid pickup housing 294. As will presently be described,fluid passageways 330 communicate with the dose control means of theinvention which, as previously mentioned, functions to control the doseof medicament to be delivered to the patient.

With the patient weight selector knob 312 in position (FIG. 47) whereininlets 310 (FIG. 49A) align with one of the groups 298 through 308 (FIG.27) of fluid passageways 296, fluid will flow from the fluid reservoirthrough inlet 297 (FIG. 22) into the fluidic micro-channels of differentlengths formed in upper and lower surfaces of lower rate control plate160 (FIGS. 36 and 40), into vertically extending fluid passageways 296of fluid pickup housing 294 (FIG. 24), into inlets 310 (FIG. 22), intopassageways 320 formed in the fluid pickup assembly 322, intopassageways 316 of the patient weight selector knob 312, intopassageways 330 of the fluid pickup assembly 294 and finally intopassageways 332 of body portion 334 a of the dose control assembly 334(see also FIG. 53A). It is apparent that the rate of fluid flow towardthe dose control means depends upon the configuration of the ratecontrol passageways formed in the rate control plate 160 that are incommunication with inlets 310 via vertically extending fluid passageways296. By way of example, assume that the patient weight selector knob 312is rotated into a position wherein inlets 310 a, 310 b, 310 c, 310 d,310 e and 310 f (FIG. 47A) align with the passageways 296 a, 296 b, 296c, 296 d, 296 e and 296 f of group 298 (FIG. 27). Assume further, thatthe six passageways 296 a, 296 b, 296 c, 296 d, 296 e and 296 f are incommunication with fluid passageways 162, 164, 166, 168, 170 and 172respectively of rate control plane 160 (FIG. 40). In this situation,fluid will flow from fluid passageway 162 into passageway 296 a, theninto passageway 310 a and finally into the lower most circumferentiallyextending passageway 320 a formed in the fluid pickup assembly 322 (FIG.7). Similarly, in this situation, fluid will flow from fluid passageway164 into passageway 296 b, then into passageway 310 b and finally intocircumferentially extending passageway 320 b formed in the fluid pickupassembly 322 (FIG. 7). The fluid will flow in a similar manner frompassageways 166, 168, 170 and 172 into the remaining circumferentiallyextending passageway 320 formed in the fluid pickup assembly 322

As illustrated in FIGS. 12 and 13 of the drawings, rate control indexingmeans are provided to position the locking knob 312 in a selectedrotational position. In the present form of the invention, this ratecontrol indexing means comprises a locking plunger 333 that is receivedwithin a bore 104 a formed in the forward portion 104 of housing 102.Locking plunger 333 is continuously biased outwardly, by a coiled spring335 into locking engagement, with a selected one of a plurality ofcircumferentially spaced apart cutouts 312 c formed in the flangeportion 312 b of the locking knob assembly 312. With this construction,in order to rotate the locking knob from the selected rotationalposition, the locking plunger 333 must be manually pushed inwardlyagainst the urging of spring 335.

Turning now particularly to FIGS. 7 and 50 through 53, rotatably mountedwithin body portion 334 a of the dose control assembly 334 is thepatient dose selector knob 338, formed within a body portion 338 a ofthe dose selector knob vertically spaced-apart radially outwardlyextending fluid passageways 340, 342, 344, 346, 348 and 350. By rotatingthe dose selector knob within body portion 334 a, the radially outwardlyextending fluid passageways can be selectively brought in tocommunication with the passageways 332 that are, in turn, incommunication with the circumferentially extending passageway 320 formedin the fluid pickup assembly 322 of the rate control means of theinvention. By way of example, in FIG. 7 of the drawings radiallyoutwardly extending fluid passageway 340 is shown in communication withthe uppermost passageway 332 of the dose control means. As illustratedin FIG. 51, each of the radially outwardly extending fluid passagewaysis in communication with an axially extending passageway 352 that is, inturn, in communication with the bolus operating mechanism of theinvention, the character of which will presently be described.

By way of example, further rotation of the dose selector knob withinbody portion 334 a can bring radially outwardly extending fluidpassageway 350 into communication with circumferentially extendingpassageway 320 a of fluid pickup assembly 322 via the lower-mostpassageway 332. In this situation, it can be seen that fluid passageway350 is in communication with fluid passageway 162 of lower surface ofrate control plate 160 via the lower most passageway 332, the lower mostpassageway 330, the lower most passageway 316, circumferentiallyextending passageway 320 a and passageway 296 a. Similarly, in thisexample, by controlled rotation of the dose selector knob, each of thefluid passageways formed in the dose selector knob can be brought intocommunication with a selected one of the passageways 164 through 172formed in the rate control plate 160. In this way the rate of fluid flowtoward the patient of the medicinal fluid contained within the devicereservoir can be closely controlled.

As illustrated in FIGS. 12 and 14 of the drawings, dose control indexingmeans are provided to lock the patient dose selector knob 338 in anyselected position. In the present form of the invention this dosecontrol indexing means comprises a locking plunger 353 that is receivedwithin a bore 104 b formed in the forward portion 104 of housing 102.Locking plunger 353 is continuously biased outwardly by a coiled spring355 into locking engagement with a selected one of a plurality ofcircumferentially spaced apart cutouts 338 c formed in the flangeportion 338 b of the patient dose selector knob assembly 338. With thisconstruction, in order to rotate the patient dose selector knob 338 froma selected position the locking plunger 353 must be manually pushedinwardly against the urging of spring 355.

Considering further the bolus delivery means of the invention, thisnovel means, which is housed within forward portion 104 of housing 102,includes a double bolus reservoir 360 that is disposed within a cavity359 formed in forward portion 104 of housing 102. The double bolusreservoir 360 is defined by interconnected, collapsible bellowsstructures 360 a and 360 b that are in communication with passageway 352of the dose control means via a longitudinally extending passageway 362,a vertical stab passageway 364, a conventional umbrella check valve 366,a vertical stub passageway 368 and a longitudinal passageway 370 (seeFIGS. 5 and 53A). Umbrella check valve 366, which is carried with aninternal housing 372, functions to permit fluid flow toward reservoir360, but blocks fluid flow in the opposite direction. Reservoir 360 isin fluid communication with the administration set 153 (FIG. 2) viapassageway 374, a second conventional umbrella check valve 376, avertical passageway 378 and longitudinally extending passageway 380.With this construction, low flow from the dose control means anyselected dose, to bolus reservoir 360 and then on to the patient via theadministration set 153.

Referring particularly to FIGS. 5A, 53A and 57-61, the important bolusoperating mechanism of the invention is there shown and generallydesignated by the numeral 384. This mechanism permits selected bolusdoses of medicaments to be delivered to the patient from reservoir 360as may be required. As best seen in FIGS. 55 and 57 of the drawings,this novel mechanism here comprises a first, or main operating shaft 386for controllably collapsing the bellows structure 360 a and a secondoperating shaft 387 (FIGS. 61, 62, 73, and 74) for controllablycollapsing the bellows structure 360 b (see FIG. 59). By way of nonlimiting example, bellows structure 360 a can have a first volume ofbetween approximately 3 ml and approximately 6.0 ml while bellowsstructure 360 b can have a second, lesser volume of approximately 0.5 mland approximately 2.0 ml. Main operating shaft 386 controllablycollapses bellows structure 360 a by pushing inwardly on the shaftagainst the urging of a coiled operating spring 388 that circumscribesbellows structure 360 a. In the manner illustrated in FIG. 55, mainoperating shaft 386 is movable within the reduced diameter portion 390 aof the bolus selector housing 390 that is carried within the forwardportion 104 of housing 102. Following rotation of the bolus selector ina manner presently to be described, the main operating shaft can bemoved inwardly against the urging of coiled operating spring 388 from anextended to an inward position. Inward movement of the main operatingshaft causes inward movement of a pusher member 394 which, in turn,causes the collapse of the bellows portion 360 a. It is to be noted thatpusher member 394 is provided with a yieldably deformable locking tab394 a (see also FIG. 62) that is adapted to engage a plurality ofgenerally saw-toothed shaped protuberances 396 that are formed on theinner wall of cavity 359. Locking tab 394 a is so constructed andarranged as to ride over protuberances 396 as the main operating shaftis pushed inwardly of cavity 359. However, the saw-toothed protuberances396 are configured so that the locking tab will engage the verticalfaces 396 a of the protuberances in a manner to prevent movement of thepusher member in a direction toward its starting position (FIG. 55).With this construction, once the reservoir bellows portion 360 a iscollapsed, it will remain in a collapsed configuration.

Following rotation of the operating knob 399 of the bolus operatingmechanism 384 in a manner presently to be described, second operatingshaft 387 can be moved inwardly within a bore 386 a provided in mainoperating shaft 386 against the urging of a second coil spring 400.Second operating shaft 387 operates against bellows portion 360 b in amanner to collapse the bellows portion as the second operating shaft isurged inwardly against the urging of spring 400. As the bellows portion360 b collapses, medicinal fluid contained there within will be urgedoutwardly of the reservoir via outlet passageway 378. However, upon therelease of inward pressure exerted against second operating shaft 387,spring 400 will urge the operating shaft into its original startingposition so that subsequent smaller bolus doses of medicament can bedelivered to the patient.

Turning now to FIGS. 59, 60 and 61, in delivering bolus doses ofmedicament to the patient, a locking member 404 that is carried byhousing 102 in the manner shown in FIG. 56 of the drawings must bepushed inwardly in order to permit rotation of the reduced diameterportion 390 a of the bolus selector housing 390. As indicated in FIG.56, inward movement of the locking member causes the locking shoulder404 a to move out of locking engagement with a cavity 390 c formed inthe enlarged diameter portion 390 b of the bolus selector housing 390 soas to permit rotation of the bolus selector housing 390. With thelocking member pushed inwardly, the bolus selector housing 390 can berotated from the “off” position shown in FIG. 59 of drawings to the “5.0ml” position. This done, the main operating shaft can be pushed inwardlycausing plunger 394 to collapse bellows 360 a, resulting in the deliveryof a bolus dose of a predetermined volume of medicament to the patient(in this case 5.0 ml). As previously mentioned, once the main operatingshaft is pushed inwardly, it will be locked in position by locking tab394 a.

When it is desired to deliver a smaller bolus dose of medicament to thepatient, as, for example 2.5 ml, it is necessary to first rotate cap 399from the “off” position shown in FIG. 77 to the “2.5 ml” position shownin FIG. 78. As best seen in FIG. 73 second operating shaft 387 isprovided with a rotational stop 387 a that engages a stop wall 410provided on the main operating shaft 390 (see FIGS. 64 through 67). Asthe second operating shaft is rotated, a coiled spring 412 carried aspring shelf 414 (FIGS. 66, 67 and 69) will resist the rotation and willbe compressed in the manner in FIG. 70.

This done, the secondary operating shaft 387 can be pushed inwardly inthe manner illustrated in FIG. 61. This inward movement of the secondoperating shaft will collapse bellows portion 360 b causing the fluidcontained there within (in this instance 2.5 ml) to be delivered to thepatient via outlet passageway 374.

With the construction described in the preceding paragraph, when therotational forces exerted on cap 399 cease, spring 412 will urge the capto return to its starting position and at the same time, spring 400 willurge shaft 387 into its starting position, thereby permitting a repeatedapplication of a smaller bolus dose of medicament to the patient as maybe required.

Having now described the invention in detail in accordance with therequirements of the patent statutes, those skilled in this art will haveno difficulty in making changes and modifications in the individualparts or their relative assembly in order to meet specific requirementsor conditions. Such changes and modifications may be made withoutdeparting from the scope and spirit of the invention, as set forth inthe following claims.

1. A dispensing device for dispensing a medicament to a patientcomprising: (a) a device housing; (b) a reservoir defining assemblycarried by said housing, said reservoir defining assembly including acollapsible reservoir having an inlet port and an outlet port; (c)stored energy means carried by said housing and operably associated withsaid reservoir defining assembly for collapsing said collapsiblereservoir to expel fluid medicament therefrom; and (d) fluid flowcontrol means carried by said device housing for controlling the flow ofmedicament from said reservoir toward said administration line, saidflow control means comprising dose control means for controlling thedose of medicament delivered to the patient and rate control means forcontrolling the rate of medicament flow from said collapsible reservoirtoward said dose control means.
 2. The dispensing device as defined inclaim 1 in which said stored energy means comprises a spring operablyassociated with said reservoir defining assembly.
 3. The dispensingdevice as defined in claim 1 in which said collapsible reservoircomprises a bellows structure.
 4. The dispensing device as defined inclaim 1 further including fill means carried by said device housing forfilling said collapsible reservoir with medicament reservoir comprises abellows structure.
 5. The dispensing device as defined in claim 1 inwhich said dose control means includes dose selector means for selectingthe medicament dose delivered to said administration line.
 6. Thedispensing device as defined in claim 1, further including a bolusdelivery assembly carried by said device housing for delivering bolusdoses of medicament to the patient.
 7. The dispensing device as definedin claim 1 in which said rate control means includes body weightselector means for selecting the body weight of the patient and the rateof flow of medicament from said reservoir to said administration line.8. The dispensing device as defined in claim 7 in which said ratecontrol means further includes a rate control plate having a pluralityof fluid flow channels interconnected with said outlet of saidcollapsible reservoir.
 9. A dispensing device for dispensing medicamentsto a patient comprising: (a) a device housing; (b) a carriage assemblydisposed within said device housing for movement between a firstposition and a second position; (c) a collapsible container carried bysaid carriage assembly, said collapsible container including anaccordion-like collapsible side wall; (d) fill means carried by saiddevice housing for filling said collapsible container with medicament;(e) a stored energy means operably associated with said carriageassembly for moving said carriage assembly between said first and secondpositions, said stored energy means comprising a coil spring having afirst end in engagement with said device housing and a second end inengagement with said carriage; (f) an administration set, including anadministration line interconnected with said collapsible container; and(g) fluid flow control means carried by said supporting structure forcontrolling the flow of medicament from said collapsible containertoward said administration line, said flow control means comprising dosecontrol means for controlling the dose of medicament delivered to thepatient and rate control means for controlling the rate of medicamentflow from said collapsible reservoir toward said dose control means. 10.The dispensing device as defined in claim 9 in which said dose controlmeans includes dose selector means for selecting the medicament dosedelivered to said administration line, said dose selector meanscomprising a selector housing carried by said device housing and aselector member rotatably carried by said selector housing.
 11. Thedispensing device as defined in claim 9, further including locking meanscarried by said device housing for locking said carriage assembly insaid first position.
 12. The dispensing device as defined in claim 9 inwhich said rate control means includes selector means for selecting therate of fluid flow between said collapsible container and saidadministration set.
 13. The dispensing device as defined in claim 9 inwhich said rate control means comprises a rate control plate having aplurality of fluid flow channels interconnected with said collapsiblecontainer; and operating means carried by said supporting structure forcontrolling fluid flow between said collapsible container and said ratecontrol means.
 14. The dispensing device as defined in claim 9 in whichsaid fill means comprises a sterile coupling assembly that includes abody portion and a pierceable septum carried by said body portion. 15.The dispensing device as defined in claim 9, further including a bolusdelivery assembly carried by said device housing and in communicationwith said administration set for delivering bolus doses of medicament tosaid administration set.
 16. The dispensing device as defined in claim15 which said bolus delivery assembly comprises a collapsible boluscontainer having a first portion of a first volume and second portion ofa second lesser volume.
 17. A dispensing device for dispensingmedicaments to a patient comprising: (a) a device housing; (b) acarriage assembly disposed within said device housing for movementbetween a first position and a second position; (c) a collapsiblecontainer carried by said carriage assembly, said collapsible containerhaving an accordion-like collapsible side wall; (d) fill means carriedby said device housing for filling said collapsible container withmedicament, said fill means comprising a piercable slit septum; (e) astored energy means operably associated with said carriage assembly formoving said carriage assembly between said first and second positions,said stored energy means comprising a coil spring having a first end inengagement with said device housing and a second end in engagement withsaid carriage; (f) an administration set, including an administrationline interconnected with said collapsible container; and (g) fluid flowcontrol means carried by said device housing for controlling the flow ofmedicament from said collapsible container toward said administrationline, said flow control means comprising dose control means forcontrolling the dose of medicament delivered to the patient and ratecontrol means for controlling the rate of medicament flow from saidcollapsible reservoir toward said dose control means, said rate controlmeans comprising selector means for selecting the rate of fluid flowbetween said collapsible container and said administration set and arate control plate having a plurality of fluid flow channelsinterconnected with said collapsible container; and (h) a bolus deliveryassembly carried by said device housing and in communication with saidadministration set for delivering bolus doses of medicament to saidadministration set said bolus delivery assembly comprising a collapsiblebolus container having a first portion of a first volume and secondportion of a second lesser volume.
 18. The dispensing device as definedin claim 17 further including operating means carried by said devicehousing for controlling fluid flow between said collapsible containerand said rate control means, said operating means comprising a piercingmember for piercing said top wall of said collapsible container.
 19. Thedispensing device as defined in claim 17 which said bolus deliveryassembly includes a first mechanism for collapsing said first portion ofsaid collapsible bolus container and a second mechanism for collapsingsaid second portion of said collapsible bolus container.
 20. Thedispensing device as defined in claim 17 in which said first portion ofsaid collapsible bolus container has a volume of between about 3 ml andabout 6 ml in which said second portion of said collapsible boluscontainer has a volume of between about 0.5 ml and about 3 ml.